There are a few optics out there that are of the reflex type that use tritium and fiber optics to be illuminated. They are always on, and do not use batteries. Trijicon makes several, but there are other manufacturers too. As with anything else though, you get what you pay for.

What kind of rifle are you using? I have a few rifles that have optics. I like to use Weaver scopes because they are good quality and I have never had a problem with them. I can't say that about Bushnell though. I use low power optics and don't really care for high power. I use a fixed 6 power on my Ruger 308. Works for me. The only red dot I have is on my HiPoint Carbine 40S&W.

I use all I can aford.Red dot Kobra on my AK,red dot TRU-GLO on my 10/22,2.5-12x40 on my FAL, .5-4xbushnell on my 12ga slug gun,etc.All my long guns have optics becouse I lost my rt eye and am rt handed,I cant use irons unless I go lefty.

Well, I know that Delta operators train for just that type of situation...
if disabled, they are ambi and will shoot with expert marksmanship from the other shoulder.
I play around with it on my .22 IT's difficult to get smooth at...

I go co-witnessed with a holographic sight on my main weapon and cheaper red dots, also co-witnessed on others. Close range is the shotgun with flash light and iron sights.
As for batteries, the holographic uses AA and Ive got plenty of rechargeables. Working on a solar system to power the recharger.